This version of
ptx contains a few features which do not exist in
ptx. These extra features are suppressed by using the
-G command line option, unless overridden by other command line
options. Some GNU extensions cannot be recovered by overriding, so the
simple rule is to avoid
-G if you care about GNU extensions.
Here are the differences between this program and System V
This program can read many input files at once, it always writes the
resulting concordance on standard output. On the other hand, System V
ptx reads only one file and sends the result to standard output
or, if a second
file parameter is given on the command, to that
Having output parameters not introduced by options is a dangerous
practice which GNU avoids as far as possible. So, for using
portably between GNU and System V, you should always use it with a
single input file, and always expect the result on standard output. You
might also want to automatically configure in a
-G option to
ptx calls in products using
ptx, if the configurator finds
that the installed
-w. All other options are GNU extensions and are not repeated in this enumeration. Moreover, some options have a slightly different meaning when GNU extensions are enabled, as explained below.
nroff. It is rather formatted for a dumb terminal.
nroffoutput may still be selected through option
-Roption is used, the maximum reference width is subtracted from the total output line width. With GNU extensions disabled, width of references is not taken into account in the output line width computations.
ptxdoes not accept 8-bit characters, a few control characters are rejected, and the tilde ‘
~’ is also rejected.
ptxprocesses only the first 200 characters in each line.
ptx, but still, there are some slight disposition glitches this program does not completely reproduce.